title: The c-Myb target gene neuromedin U functions as a novel cofactor during the early stages of erythropoiesis.
abstract: The requirement of c-Myb during erythropoiesis spurred an interest in identifying c-Myb target genes that are important for erythroid development. Here, we determined that the neuropeptide neuromedin U (NmU) is a c-Myb target gene. Silencing NmU, c-myb, or NmU's cognate receptor NMUR1 expression in human CD34(+) cells impaired burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) formation compared with control. Exogenous addition of NmU peptide to NmU or c-myb siRNA-treated CD34(+) cells rescued BFU-E and yielded a greater number of CFU-E than observed with control. No rescue of BFU-E and CFU-E growth was observed when NmU peptide was exogenously added to NMUR1 siRNA-treated cells compared with NMUR1 siRNA-treated cells cultured without NmU peptide. In K562 and CD34(+) cells, NmU activated protein kinase C-βII, a factor associated with hematopoietic differentiation-proliferation. CD34(+) cells cultured under erythroid-inducing conditions, with NmU peptide and erythropoietin added at day 6, revealed an increase in endogenous NmU and c-myb gene expression at day 8 and a 16% expansion of early erythroblasts at day 10 compared to cultures without NmU peptide. Combined, these data strongly support that the c-Myb target gene NmU functions as a novel cofactor for erythropoiesis and expands early erythroblasts.
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Julia E
authors.initials: JE
authors.lastname: Gambone
authors.forename: Stephanie S
authors.initials: SS
authors.lastname: Dusaban
authors.forename: Roxana
authors.initials: R
authors.lastname: Loperena
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakata
authors.forename: Susan E
authors.initials: SE
authors.lastname: Shetzline
mesh_terms: D015153:Blotting, Western; D002454:Cell Differentiation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D003114:Colony-Forming Units Assay; D004900:Erythroblasts / Q000378:metabolism*; D015672:Erythroid Precursor Cells / Q000378:metabolism*; D004920:Erythropoiesis / Q000502:physiology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D009479:Neuropeptides / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology; D020598:Proto-Oncogene Proteins c-myb / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D009479:Neuropeptides; D010446:Peptide Fragments; D020598:Proto-Oncogene Proteins c-myb; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017981:Receptors, Neurotransmitter; C082444:neuromedin U receptor; C056900:neuromedin U; D008156:Luciferases